Fix Index upgrade

Seems like syntax error:
- autoupdate not working due to variable is unset
- without this change (just comment this line) Indexes was not updated

Signed-off-by: SAMI BETTAYEB <[email protected]>

Author: loryk

lib/migration.js

@@ -783,8 +783,7 @@ function mixinMigration(PostgreSQL) {
           if (identical && siKeys.length > 1) {
             if (siKeys.length !== i.keys.length) {
               // lengths differ, obviously non-matching
-              // ??? orderMatched is not defined and not used anywhere else
-              // orderMatched = false;
+              identical = false;
             } else {
               siKeys.forEach(function(propName, iter) {
                 identical = identical && self.column(model, propName) === i.keys[iter];